1. Field of the Invention
The present invention relates to a cassette telephone answering device wherein, during remote controlled playout of previously received messages, the cassette drive motor itself provides the primary motive force to transfer the device into rewind prior to automatic message playout.
The present application is related to the inventor's Disclosure Document No. 100275 filed May 21, 1981 entitled "Power-Assist Rewind Function for (Remote-Triggered) Telephone Answering Device."
2. Description of the Prior Art
Remote controlled playout of previously recorded incoming messages is a highly desirable feature in a telephone answering device. It allows the user to receive his messages while he is away from home or office. To do this, the user calls his own telephone number. As the call is being automatically answered by the answering device, the user transmit a beep tone, security code or other control signal over the telephone line. Receipt of this remote control signal causes the telephone answering device to interrupt the answering cycle, to rewind the incoming message record tape, and thereafter to play back the messages from that tape via the telephone line to the user.
To facilitate such remote controlled playout operation, the answering device must have a means for transferring the drive mechanism for the incoming message tape from the forward (record or play) condition to the rewind mode, and for replacing the drive mechanism in the forward mode when rewind is complete. In the past, such drive transfer mechanisms have required either an additional motor or a relatively high powered solenoid to accomplish the transfer. Both techniques are relatively costly, precluding their use in a telephone answering device of very low cost. By contrast, it is an objective of the present invention to provide a low cost telephone answering device having remote controlled playout capability.
Typical of the prior art remote playout control mechanisms using an additional motor to accomplish the message tape drive transfer operation are the inventors' U.S. Pat. No. 4,104,487, No. 4,197,426, No. 4,201,888 and No. 4,236,044. In each of these, a separate motor operates a cam assembly which transfers the incoming message tape drive between the forward and rewind conditions. An object of the present invention is to provide a drive transfer mechanism which does not use a separate motor, but which instead uses motive power provided by the tape drive motor itself to accomplish the transfer from forward to rewind condition.
Prior art solenoid-type transfer mechanisms have required a fairly high powered solenoid to accomplish the drive transfer and to retract the recording head away from the message tape during the remote controlled rewind operation. Such a hefty solenoid is required to overcome the roughly one pound of force which typically is exerted to maintain the recording head in secure contract with the incoming message tape. Moreover, the utilized power supply must be able continuously to maintain the solenoid in the actuated condition. This is so since qualification tests, such as those performed by Underwriters Laboratories, assume that the solenoid actuating circuitry may become "stuck" with the solenoid energized. Thus the power supply must be capable of continuously supplying the high current required by the solenoid. This adds to the cost and size of the unit. Another object of the present invention is to provide a drive transfer mechanism which uses a very low powered solenoid to initiate the drive transfer, but which uses motive power supplied by the tape drive motor itself to accomplish the actual transfer from the forward to the rewind mode. This eliminates the need for a high continuous current power supply for the solenoid.
In the inventor's copending U.S. patent application Ser. No. 260,360 filed May 4, 1981 and now U.S. Pat. No. 4,385,205, there is disclosed a cassette drive assembly for a telephone answering device in which a single motor alternately drives only the outgoing announcement tape cassette or only the incoming message tape cassette, depending solely upon the direction of rotation of the motor. Such a system is particularly advantageous since only a single drive motor is required, thereby minimizing the unit cost. Moreover, since only one or the other of the tape cassettes is driven at one time, the answering announcement is not recorded onto the incoming message tape, so that one incoming message immediately follows another on that tape. This maximizes the number of incoming messages which can be recorded on the cassette, and minimizes the playback time needed for the user to listen to his messages. A further object of the present invention is to provide a telephone answering device having a single motor cassette tape drive mechanism such as that disclosed in the inventor's copending U.S. patent application Ser. No. 260,360 but configured for remote controlled playout of the recorded incoming messages.
Another desirable feature in a telephone answering device is a remote controlled fast forward capability. This allows the user, when playing back messages under remote control, rapidly to skip over those which he does not wish to hear. It is particularly useful e.g., for rapidly scanning through the incoming message tape to find a particular message. A further object of the present invention is to provide an inexpensive tape cassette drive mechanism which readily can be transferred to a fast forward mode under remote control.